An interference with existing structures is prevented at a time of a lifting construction of a boiler module. When the boiler module is lifted from the ground by lifting jacks provided on a steel frame main-beam and made an install construction to the main-beam, lifting jacks enabled to move laterally on the main-beam are disposed at forward and backward thereof to suspend the boiler module. The suspended module is lifted up to the main-beam and installed while changing a suspending position between an interference preventing position with existing modules and a prescribed suspending position by alternately moving the forward and backward lifting jacks laterally.